tree-ring research

Tree-Ring Lab (TRL) scientists are dedicated to expanding the use and application of tree-ring research around the world to improve our understanding of past climate and environmental history. Current research concentrates on the use of tree-ring data networks to study regional climate, global climate teleconnections and anthropogenic impacts on forest growth.

Exploring new species in new regions, building collaborations around the world, and developing new quantitative techniques, TRL researchers are committed to advancing dendrochronology and paleoclimatology, as well as the ethic of good science

A new study of tree rings from Mongolia dating back more than 1,000 years confirms that recent warming in central Asia has no parallel in any known record. In recent decades, temperatures have been ascending more rapidly here than in much of the world, but scientists have lacked much evidence to put the trend into a long-term context. The study does not explicitly raise the issue of human-induced warming, but is sure to be seen as one more piece of evidence that it is at work. The study appears in the journal Quaternary Science Reviews.

Four years ago this month, archeologists monitoring the excavation of the former World Trade Center site uncovered a ghostly surprise: the bones of an ancient sailing ship. Tree-ring scientists at Columbia University’s Lamont-Doherty Earth Observatory were among those asked to analyze its remains for clues about its age and origins. In a study now out in the journal Tree Ring Research, the scientists say that an old growth forest in the Philadelphia area supplied the white oak used in the ship’s frame, and that the trees were probably cut in 1773 or so—a few years before the bloody war that established America’s independence from Britain.

Researchers studying the rings of ancient trees in mountainous central Mongolia think they may have gotten at the mystery of how small bands of nomadic Mongol horsemen united to conquer much of the world within a span of decades, 800 years ago. The rise of the great leader Genghis Khan and the start of the largest contiguous empire in human history was propelled by a temporary run of nice weather.

Dendrochronologist Brendan Buckley’s usual occupation is drilling straw-like cores from old trees and extracting information about past climates by studying their rings. To extend the record beyond the time of living trees, he sometimes takes samples from long-dead trees, or even from timbers in ancient buildings. In 2010, the Lamont-Doherty Earth Observatory scientist was part of a team that traveled into the remote Cardamom Mountains of southern Cambodia to investigate human burials contained in coffins carved from entire logs.

A team led by Kevin Anchukaitis of the Lamont-Doherty Earth Observatory Tree Ring Lab is currently in Alaska’s Arctic National Wildlife Refuge, studying the effects of changing climate on trees. Ferried in by a bush pilot who landed on the tundra to drop them off, they are practically at treeline–the place where it is too far north for trees to grow. But there are still some spindly white spruces here, and they are taking cores from these, which can be used to measure weather of the past.

El Niño and La Niña, the periodic shifts in Pacific Ocean temperatures, affect weather around the globe, and many scientists have speculated that a warming planet will make those fluctuations more volatile, bringing more intense drought or extreme rainfall to various regions.

Scientists have long known that large volcanic explosions can affect the weather by spewing particles that block solar energy and cool the air. Some suspect that extended “volcanic winters” from gigantic blowups helped kill off dinosaurs and Neanderthals...

A 2005-2007 dry spell in the southeastern United States destroyed billions of dollars of crops, drained municipal reservoirs and sparked legal wars among a half-dozen states—but the havoc came not from exceptional dryness but booming population and bad planning, says a new study.

Climate researchers have shown that big volcanic eruptions over the past 450 years have temporarily cooled weather in the tropics—but suggest that such effects may have been masked in the 20th century by rising global temperatures

Researchers from the Lamont-Doherty Earth Observatory of The Earth Institute at Columbia University have used 835 annual tree-ring chronologies based on measurements from 20- to 30-thousand tree samples across the United States, Mexico, and parts of Canada to reconstruct a history of drought over the last 2005 years. The resulting drought reconstructions have been organized into a North American Drought Atlas CD-ROM, the first of its kind, which maps year-by-year occurrences of droughts.

Severe drought in western states in recent years may be linked to climate warming trends, according to new research, led by scientists from the Lamont-Doherty Earth Observatory of The Earth Institute at Columbia University, to be published in the journal Science. This research was supported by the National Oceanic and Atmospheric Administration (NOAA) and the National Science Foundation (NSF).